An apparatus which is known from U.S. Pat. No. 3,877,505 has a receiving device to which the rim of a motor vehicle wheel can be fixed. The receiving device can be rotated during the fitting or removal operation by means of a rotary drive device, for example an electric motor. The tyre can be fitted to the rim or released from the rim by means of fitting or removal tools. Provided on the removal tool is a sensing device in the form of a projection which senses the radial outside surface (rim bed) of the rim and which comprises a material which does not damage the rim material, for example plastic material. That ensures that the removal tool is kept at a given spacing from the surface of the rim in the removal operation. That prevents the rim surface being damaged by the hard material of the removal tool. In that case however there is the danger that the projection which senses the rim contour and which maintains the spacing wears away due to abrasion or is damaged in some other fashion.
It is also known from EP 1 995 083 to sense the position of the rim contour along which the fitting or removal tool is guided in a contact-less manner. Afterwards, the movement of the fitting or removal tool is guided in dependence on the sensed contour without contacting the rim surface.
EP 1 927 484 shows a sensing device for contact-less sensing. Thereby, the sensing device is preferably based on the principle of optical laser triangulation. The sensing device provides a light source that emits a light beam onto the surface in one or more given positions and intersects the rim surface in a plurality of impingement points. At each of the impingement points, the light beam is scattered in a plurality of light rays that are reflected. These reflected light beams were detected by a detector. The spacings and thus the positions of the impingement points sensed at the wheel or the rim can be determined in dependence on the directions of the emitted and reflected light beams by triangulation. The sensed points are detected in a three-dimensional manner and the coordinates of the sensed points (X, Y and Z values) are known.